Historic Resources Survey

The Historic Resources Survey is the document that classifies every parcel in an HPOZ. Each district has its own Survey, prepared during the establishment of the HPOZ by qualified historic preservation professionals and certified by the Cultural Heritage Commission before the district takes effect. Once certified, the Survey is incorporated by reference into the adopted Preservation Plan.

Per the citywide HPOZ Ordinance, the Survey is a document that identifies all Contributing and Non-Contributing structures and all Contributing landscaping, natural features, and sites — individually or collectively, including street features, furniture, and fixtures.

The Survey decides what classification each parcel carries. It does not, by itself, decide what review applies, what design guidelines govern, or what work is permitted. Those questions are answered by the citywide HPOZ Ordinance, the procedural framework now codified at Division 13B.8 of Chapter 1A, and the district’s adopted Preservation Plan — which use the Survey’s classification as an input.

In practice this means a project review on an HPOZ property reads three documents at minimum:

• The Survey tells you what the structure is — its classification and the character-defining features identified on the parcel.
• The Preservation Plan tells you what design guidelines and Conforming Work delegations apply to that classification in this district.
• The citywide ordinance and Chapter 1A procedural framework tell you which review procedure governs the proposed work and what the appeal pathway is.

Owners and design teams who treat the Survey alone as the answer to “what can I do” miss the other two-thirds of the system. The Survey is the foundation. The Plan and the ordinance are the structure built on it.

Adopted Preservation Plans across the LA HPOZ system use four classifications, drawn from the citywide framework. The Department of City Planning’s current public-facing language consolidates these into two for project-review purposes — Contributing (which includes Contributing-Altered) and Non-Contributing — but the underlying Plan distinctions remain operative within each Survey.

A structure, landscape feature, or site identified in the Survey as Contributing — generally because it was built within the district’s Period of Significance and retains elements that identify it as belonging to that period. In some cases, structures built outside the Period of Significance are designated Contributing because they are compatible with the district’s historic context or because they are historic in their own right.

Per language drawn directly from adopted Preservation Plans, “Contributing Altered structures are structures that date from the Period of Significance, and have retained their historic character in spite of subsequent alterations or additions, where the alterations are deemed reversible.” The classification recognizes that historic character can survive imperfectly: a structure that has been modified in ways that could be undone retains Contributing status, while one altered beyond reasonable reversal does not. Some Plans treat Contributing-Altered as a separate classification line; the Department of City Planning’s current public-facing system folds it into Contributing.

Per the citywide framework as restated in adopted Preservation Plans: “Non-Contributing structures are those structures, landscapes, natural features, or sites identified as not retaining their historic character as a result of irreversible alterations; having been built outside of the HPOZ Period of Significance; being a vacant lot; or being an unpermitted structure or addition.”

The four sub-types within Non-Contributing matter because the design guidance applicable to alterations or new construction can differ depending on which of the four conditions produced the classification:

• Irreversible alterations. Properties built within the Period of Significance whose alterations are deemed not reversible. These structures may retain massing, building forms, and styles consistent with the district’s development pattern even where the original details cannot be restored.
• Built outside the Period of Significance. Structures whose construction date falls outside the district’s historic period.
• Vacant lots. Per Plan language: un-built lots, or lots that do not have legally permitted structures.
• Unpermitted construction. Structures or additions built without proper permits, which therefore are not part of the legally existing built fabric the Survey records.

Owners can pull the recorded Survey designation, but Department of City Planning staff applies the classification during project review. The two are not the same step.

Survey designation is publicly accessible:

• ZIMAS. The City’s Zoning Information and Map Access System at zimas.lacity.org. The HPOZ designation and Contributing status appear with the parcel record.
• Office of Historic Resources. The full Survey for each district — including individual property records, photographs, the architectural style classification, and the reasons for the classification — is maintained at OHR.

Pulling the designation is the easy part. Applying it to a specific project — deciding which character-defining features are implicated, whether a proposed alteration affects them, and which review procedure follows — is staff work. The OHR planner assigned to the district reads the proposal against the Survey record and the applicable Preservation Plan and determines how the classification governs the application. Owners do not self-classify, and the headline ZIMAS designation does not by itself dictate every detail of the review path.

The Survey classification is the input the rest of the HPOZ system runs on. Every review category depends on it in some form:

• Certificate of Appropriateness (COA). COA review is triggered specifically by significant work proposed for a Contributing element. The Survey identifies which elements are Contributing.
• Certificate of Compatibility (CCMP). CCMP review applies to new construction on vacant lots and to demolition-and-replacement of Non-Contributing structures. Both triggers come from Survey classifications.
• Conforming Work on a Contributing Structure (CWC). Maintenance, repair, restoration, and alterations on a Contributing structure proceed under CWC. The track exists only because the Survey says the structure is Contributing.
• Conforming Work on a Non-Contributing Structure (CWNC). The parallel track for Non-Contributing structures. Same logic in reverse.
• Exempt Work. Several exemptions in the citywide framework — for example, certain Department of Public Works improvements in the right-of-way — are conditioned on the Survey not identifying any Contributing elements in the affected area.
• Street Visible Area. Visibility analysis cross-references the Survey to identify which Contributing elements are in the line of sight from the public realm. The same physical visibility can carry different review consequences depending on whether the visible elements are Contributing.
• 20% Building Coverage Threshold. The threshold itself is calculated against the Building Coverage legally existing on the effective date of the HPOZ rather than directly against the Survey, but the Survey’s designation of Contributing structures and accessory features informs which existing footprint is being measured against and which character-defining features the proposed addition must navigate.

The Survey is upstream of all of these. A change to the classification — for example, a successful re-survey that reclassifies a structure from Non-Contributing to Contributing — propagates down to every review category that follows. The Survey is the document that, more than any other, decides what an HPOZ property is and is not.

Surveys are conducted by qualified historic preservation professionals, typically under contract with the Office of Historic Resources during the establishment of an HPOZ. Survey work follows the procedures set forth in the citywide ordinance in effect during the period the Survey is conducted. Recent Surveys have been completed by firms specializing in historic preservation; certification dates appear in the adoption resolution for each district.

Surveys are not necessarily static after certification. Per the procedural framework, an existing Survey may be amended through a defined process — for example, when a property is reclassified following restoration of original elements, or when new information about a structure’s history comes to light. The amendment process runs through OHR and the Cultural Heritage Commission and is a separate workflow from project-by-project review.

Source: Citywide HPOZ Ordinance (LAMC §12.20.3) and Division 13B.8 (Historic Preservation), Chapter 1A LAMC. Survey definition and classification language drawn from adopted Preservation Plans across the LA HPOZ system; the Contributing-Altered language and the four Non-Contributing sub-types quoted directly from district plan language in the materials reviewed for this entry. Public-facing classification consolidation (Contributing including Contributing-Altered; Non-Contributing) per Department of City Planning, Historic District Project Review (planning.lacity.gov/preservation-design/historic-district-project-review). Survey access via ZIMAS (zimas.lacity.org) and the Office of Historic Resources.